Cooked it last night, must reheat it tonight in an oven. What temp/time for best results?

I made Greek Lemon Chicken (sorta based on a Thibeault's Table post) last night. I'm taking it to my sister's for dinner tonight, and she expressly doesn't want it reheated in the microwave. (She's going through chemo, so she gets to be picky right now.)

I was going to put it in the oven (large roasting pan, covered with foil) and I was wondering how long and at what temp would be best to reheat but not overcook? (Actually, now that I think about it some more, I guess I could put it in a pot on the stove and gently warm it...)

I cut up a whole chicken, browned it in a pan, put in some kalamata olives, oregano, juice of 2 lemons and some chicken broth and put it in the oven (covered) for 20 minutes. Then I was supposed to add potatoes and cook for another 20 mins. (But the chicken was cooked by then so I took out the chicken and just cooked the potatoes in the sauce for a while.

It has been sitting in the frig since last night (chicken, potatoes and sauce, all together). While there is some liquid in there, it is not like a stew, which is why I was thinking of reheating in the oven as opposed to on the stove.

Any recommendations? (My search for "reheat" turned up a lot of posts for reheating steak or pizza!)

Set it on the counter until it comes to room temp, THEN heat, preferably in the oven. IME, the stovetop creates more of that "reheated leftover" flavor in meat than does the oven or microwave. The important thing is to apply no more heat than necessary to get it to serving temp, hence the room temp before heating. It does not need to get higher than 120F, if that.